32
b.Reliabilityof Test
Reliability isone of the characteristics of good test. It refersto the consictencyofthemeasurement.NurkancanaandSumaratana1986:131state,
“The reliability ofatestistheextendtowhichitgivesconsistentresultwhenappliedby different
peopleorondifferentoccasions”.Itmeans thatifthescoresofthestudents
arestableapplyingitbydifferentpeopleorondifferentoccasionsthenthetestis reliable. But,if the score tends to fluctuate too much, the test is unreliable. Reliability
isoneofthecharacteristicsofgoodtest.Itreferstotheconsistencyofthe measurement. Lado 1961:31
says, “Reliability
is measured
by a correlation between thescoresofthesamesetofstudentsontwoconsecutiveadministrationsof
thetest.”Itmeansthat ifthescoresofthestudentsarestableapplying
itby different peopleorondifferentoccasionsthenthetestisreliable.But,ifthescoretendsto fluctuate
toomuch, thetest isunreliable. Inthisresearch,Thewriterhastreated
the20142015tenthyearstudents equally.Thewriterpreparedfiftyquestionsandforeachitemwouldbegiventwo
point.So,everystudentwillgetscoreasshehecould.Thewriterexaminedtheir answer-
sheetsinthesameway.Thewriterwillusethefollowingformulasuggested byKuder – Richarson:
KRr=
� ��−
�
[ �−
� ��−�� ��.��
�
]
Which: r
=reliabilityof the instrument k =number of questions
M = mean ofthetestscore
S
2
=standard deviation
33
c. Scorability
Scorabilityinanassessmentisthemostbasicthingastodeterminewhether anassessmentisvalid.Thismeansthatwhetheragiventestscoreslateron can be accurately
sothattheresultsobtainedarevalid.Intheassessmenttest,anexaminer shouldbecarefulintermsofscorabilities,becauseitisonethatissensitiveofthe
assessmenttestisscoring.AccordingtoLado1961:31,“Objectivetestsareeasy to
score.”Itiscausedbytheassessmentcanbemadeobjectivelybyeliminatingthe personalopinionoftheexaminer.Ifatestgetssteadily
assessmentresults,withthe sameresult,doesnot
changeevenif theassessmentwastobyperformed
bydifferent examiners, thetest isvalid.
d. Economy
Lado1961:31saidthatifthe testmeasurewhatwewantitinareasonable
timeconsidering thetesting
situation,itwillbepracticalandeconomical.Itmeans thatagiventestshould haveareasonable time, not toofastand not toolong.Thetest
shouldprovidesufficientinformationin accordancewith thetime that isgivenin order to thetestresultsareobtained asexpected.
e. Administrability